A public-interest law firm filed a lawsuit challenging the president's authority to unilaterally impose tariffs, at least the fifth such lawsuit since Donald Trump's "Liberation Day" tariffs.

Stonemaier Games, an American board game company, said in a federal lawsuit that it could soon face a $1.5 million payment to its China-based manufacturing partner.

Trump announced and then suspended wide-ranging tariffs on dozens of countries on April 2. He suspended most of those tariffs seven days later, but kept a 10% baseline tariff and a 145% tariff on imports from China.

"We will not stand idle while our livelihood – and the livelihoods of thousands of small business owners and contractors in the U.S. – are treated like pawns in a political game," said Jamey Stegmaier, co-founder of Stonemaier Games. "We now face a $14.50 tariff tax for every $10 we spent on manufacturing with our trusted long-term partner in China."

The lawsuit, filed in the Court of International Trade, seeks to stop implementation of the tariffs. Pacific Legal Foundation, a national nonprofit law firm, filed the suit on behalf of Stonemaier Games and other small businesses.

"The Constitution grants Congress, not the president, the power to impose tariffs. The president cannot assume this power for himself, and Congress can’t transfer that legislative authority to him,” said Molly Nixon, an attorney at Pacific Legal Foundation. "The uncertainty many Americans are experiencing shows why the Constitution gives the power to make laws to the representative and deliberative branch of government."

Pacific Legal Foundation isn't alone. The New Civil Liberties Alliance, Tranel Law, and Liberty Justice Center have filed similar suits. California also filed suit. Arizona and Oregon did the same, joined by Colorado, Connecticut, Delaware, Illinois, Maine, Minnesota, Nevada, New Mexico, New York and Vermont.

Trump has promised tariffs will make the U.S. wealthy, bring back manufacturing jobs lost to lower-wage countries in decades past, and shift the tax burden away from U.S. families.

A tariff is a tax on imported goods. The importer pays the tax and can either absorb the loss or pass the cost on to consumers through higher prices.